摘要:在机场、道路等大型基础设施建设的过程中，根据土体类型、按照一定的坡度直接放坡是边坡处理的常见方法之一。现有BIM软件的相关功能虽能在一定程度上满足坡脚线推算和边坡土方量统计的需求，但在机场地势优化设计的参数正向设计过程中，反复使用软件功能的时间成本较高，不利于最终方案的得出。针对该问题，本文提出一种坡脚线的推算方法，即通过建立坡面和地面的数学模型，依托Civil 3D平台进行二次开发，实现了坡脚线的自动生成及可视化。与已有的传统作图法及BIM的相关功能相比，其具有适合计算机求解、计算速度快等优点，在机场地势优化设计等需要多次建模求解的过程中具有较高的应用价值。

Abstract: One of the commonly used methods for slope treatment in large-scale infrastructure projects such as airports and roads is to directly set slopes based on soil type and a certain slope. Although existing BIM software provides certain functions to meet the needs of toe line calculation and slope earthwork volume estimation, the repeated use of software functions during the parametric design process of airport terrain optimization results in high time costs and low efficiency. To address aforementioned issues, this paper proposes a method for calculating toe lines by establishing mathematical models of the slope and ground, and developing a Civil 3D plug-in using C# to realize automatic visualization generation of toe lines. Compared with the traditional manual drafting methods and existing BIM functionalities, it has the advantages of being suitable for computer solving and having fast calculation speed, which demonstrates high practical value for the projects that involve model generation and solution iteration.